send.cs

...
private UdpClient sending_UdpClient   = new UdpClient();
private void timer1_Tick(object sender, EventArgs e)
{
    float throttle = throttle_trackBar.Value;
    throttle /= 10;
    throotle_textBox.Text = throttle.ToString();

    float elevator = elevator_trackBar.Value - 10;
    elevator /= 10;
    elevator_textBox.Text = elevator.ToString();

    float aileron = aileron_trackBar.Value - 10;
    aileron /= 10;
    aileron_textBox.Text = aileron.ToString();

    // add "," separators and new line at the end
    // as desribed in inputprotocol.xml
    String str = aileron.ToString() + "," + elevator.ToString() 
                 + "," + throttle.ToString() + "\n";

    Byte[] sendBytes = Encoding.ASCII.GetBytes(str);

    sending_UdpClient.Send(sendBytes, sendBytes.Length, "127.0.0.1", 49000);
}
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